People who dance usually train in front of mirrors, to better check their moves. That's possible for skateboarders as well, right? Those guys might want to check their manoeuvres the best possible way.

I think its actually saying that the owner of the house likes sneakers so much that the whole house has mirrored skirting boards, an object is needed in the space to show it's reflections, so you know it's mirrors, however the skateboard confuses the intended message and makes the whole thing confusing.

well could have been nice if only the floor wasn't this way. must be hard to roll on this surface. perhaps a wooden floor like those on half pipes could have helped.
Took me time to get it because of this.